Clamp.



A. 1. THOMSON.

CLAMP.y APPLICATION FILED MAR. 22. 1917.

, mma Apr. 23, 19118.

llldliTFl ALFRED J'. THOMSON, OF CANTON, MASSACHUSETTS.

CLAMP.

Application led March 22,

To all whom it may concern.'

Be it known that 1, ALFRED J. THOMSON, a citizen of the United States of America, and a resident of Canton, in the county of Norfolk and Commonwealth of Massachusetts, have invented certain new and useful improvements in Clamps,"ot which the following is a specification.

This invention relates to clamps for use in stretching hides and skins, the object being to provide a device of this character which is adapted to be used without perforating the edges of the hide or otherwise injuring the same.

To this end the main portion or body of the clamp is provided with a jaw at one end and has ears to the outer ends of which is pivoted one end of the clamping lever which is provided intermediate its ends with a curved cam surface adapted to coact with said jaw and force the hide not only against said jaw but also against the under face of the plate forming the body portion of the clamp.

.The invention consists in certain novel features of construction and arrangement of parts which will be fully understood by ref erence to the description of the drawings and to the claims hereinafter given.

For the purpose of illustrating the invention one preferred form thereof is illustrated in the drawings, this form having been fon nd to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which the invention consists can be variously arranged and organized and that the invention. is not limited to the precise arrangement and organization of these instrumentalities as herein shown and described.

Of the drawings: n

Figure 1 represents an elevation of a clamp embodying the principles of the present invention. i

Fig. 2 represents an inverted plan of the same.

Fig. 3 represents a longitudinal section on line 3-3 on Fig. 2.

Fig. 4c represents an elevation of one end ofthe same, and

Fig. 5 represents an elevation of the opposite end of the same.

Similar characters designate like parts throughout the several gures of the drawings.

n the drawings, the body portion of the Specification of Letters Patent.

Patented Apr. 23, 1916..

191?. Serial No. 157,043.

clamp consists of the plate 10 havingv a 'j aw 11 at one end and the downwardly and forwardly extending ears 12 on the opposite sides of said plate 10. The rear end of the plate 10 is provided with an eyelet 13 through which is adapted to be secured one drical openings 141 extending therethrough into which project the pintles l5 on the end of the pivoted lever V16.71ntermediate its ends'the lever 16 is provided with a curved cam surface 17 adapted to coact with the jaw 11 to grip the leather or skin 18 being stretched. v

The lever 16 is alsoprovided with a portion 1SX which is substantially.parallel with the plate 1() when the hide or skin 18 is being stretched. The other end 19 of the lever s 16 is inclined away from the plate 10, as indicated in Figs. 1 and-3 of the drawings, thereby providing means whereby 'the lever may be moved about the pivot 15 into its inoperative position. l

By bending the plate 10 upwardly adj a cent to the jaw 11, as indicated at 20, provision is made whereby the hide when stretched is retained in a perfectly dat and horizontal position so that the liquid used to linish the hide or skin is prevented from settling in spots around the edges of said hide or skin.

This settling of the liquid in this manner is very objectionable, and often incurs additional labor in finishing the hide. Y

The portion 20 of the plate 10 is mad somewhat yielding so that when the lever 16 is operated to clamp the material 1S between the jaw 11 and the curved portion 17, said portion 20 is adapted to yield to accommodate itself to various thicknesses of material. By providing the cam surface 17 to the lever 16 intermediate its ends, a smooth surface is always brought into contact with the material and injury thereto is prevented.

It is obvious that the more strain that is brought upon the hide or skin 18 the greater will be the clamping effect between the cam portion 17 and jaw 11. The lever 16 is proilo vided with lateral projections 17X adapted to engage the front face of the ears 12 and thereby limit the movement of the lever 16.

When it is moved about its pivot 15 away from the plate 10 to permit the insertion of the hide between the cam surface 17 and the aw 11, it is obviously desirable to limit the movement of said lever, which is accomplished by the projections 17X.

The. jaw 11 is slightly outside of a line perpendicular to the plate 10 and extending through the axis 'of vthe pivots 15. As a conseqence of this location of the jaw 11 rela` tively to the pivots 15,A it is obvious that considerable forcemust be applied to the end 190i the lever 16 to move the cam surface '17 by the jaw 11-7 thereby making impossible any accidental displacement of said Y lever 1G. llt is obvious, therefore, that When the leverv 16 ismoved about its pivots 15 in either directio'n'the initial action oi: the cam vsurface 17 will be to 'more "rmly clamp the material against the jaw 11.

vrPhi-s makes a very simple construction of clamp for use in `stretching' hides and skins,

which is vinexpensive to manuztactnre and very effective in lits operation'. f

t believed hat the operation and many Y advantages rof this invention will be fully understood from theor-egoing description.

Having thus described my invention, I claim: Y v Y El. a device of the class described, the

V'combination of a plate having Vside ears eX- tend-ing downwardly therefrom with their 'outer ends separated from said plate `and said plate being Vprovided Ywith an extension beyond the base of said :ears terminating in a' .sharp edged jaw; and a lever pivotally lmounted at one end'in said ears, sai-d lever consisting of a plafte formed between its pivots fand its opposite end avit'h a curved said plate being provided with an extension beyond the base of said ears terminating in a sharp `edged jaw, the edge of which is substantially in the plane of the under face of said plate; and a lever pivotally mounted at one end in said ears, said lever consisting of a plate formed with a curved cam portion adapted to cO-act with said jaw and so arranged that the strain on the clamped material Will cause said cam portion to more firmly clamp said material.

3. In a device of the class described, the combination of a plate having side ears cxtending downwardly therefrom with their outer ends separated from said plate and said plate being provided with an outwardly curved extension beyond the base of said ears terminating in a sharp edged jaw; and a lever pivotally mounted at one end in said ears, said lever consisting oli. a plate formed with a curved cam portion adapted to co-act with said jaw and so arranged that the strain on the clamped material. will cause said -cam portion to more 'rnily clamp said material.

at. In a device of the yclass described, the combination o'f a plate having side members extending doxvmvardly therefrom and provided With perforated ears projecting forwardly Vbeyond the base of :said side inembers and said plate .also having a curved extension termin-ating in a sharp edged jaw substantially opposite the axes of the perfor-ations in said ears; and a lever pivotally mounted at one end in said ears, said lever consisting' of a plate provided at one :end 'with trunnions positioned in .said perforations and having formed therein between its .trnnnions and 'the opposite end a .curved cam portion an 'intermediate 'part of which is Aadaptecl to co-:act with said jaar :and so arranged that the strain on the .clamped material will cause :said :cani portion to more firmly vclamp said material.

Signed by ine at 4 Bost @hice Sq., Bosa-Ion, Mass., this 19th of March, 1917.

ALFRED J.. THOMSON. Witnesses:

WALTER E LOMBARD, NATHAN C. LOMBARD.

Gnptc of fthis .gaitentrmay be 'robtaine im' 'five cents each, 'by addressing the Commissioner at Patents,

Washington, D. C. 

